Soap and water not enough to kill all harmful bacteria

CLEANING your kitchen top and chopping board with soap and water is not good enough, as harmful bacteria that cause diseases may still lurk on the surfaces.

This is because soap and water do not kill all bacteria, which could remain on household surfaces and spread via cleaning cloths. A more effective way of removing such pathogenic bacteria is by using disinfectants and antibacterial cleaners, said a study released yesterday.

The four-week-long Dettol Bacterial Survival Study was conducted in Britain earlier this year by the Global Hygiene Council, an initiative that brings together global experts in various fields, including microbiology and infectious diseases.

The study was reviewed by Associate Professor Paul Anantharajah, a senior consultant with the Department of Medicine at the University Medical Cluster of the National University Health System in Singapore.

Five types of bacteria - including E. coli and salmonella - that can cause serious food poisoning were tested to see how long they would survive on surfaces like plastic, stainless steel and fabric.

The bacteria were tested at three different temperatures: 4 deg C, 18 deg C and 25 deg C.

The staphylococcus bacteria, commonly found on healthy human skin and in nasal passages, were found to be capable of surviving for as long as 48 hours on plastic surfaces at 25 deg C - the temperature of tropical countries like Singapore.

The five bacteria were also found to survive most favourably at 4 deg C, the temperature of a refrigerator. This shows that a fridge, despite its low temperature, can be a bacteria breeding ground too.

Prof Anantharajah said: "The study reinforces the...message that people need to be careful about what they are doing at home."

In a separate study, it was found that people who are well-informed about germs and contamination were five times more likely to wash their hands with soap. And those who cover their nose and mouth when they sneeze and cough were about 2.5 times more likely to report low levels of infection.

These findings were part of a four-month global Dettol Habit Study, which polled 12,000 people across 12 nations, such as China, Germany and Malaysia.